187 research outputs found
The roles of inter-fuel substitution and inter-market contagion in driving energy prices: evidences from China’s coal market
Coal has been dominating energy supply and consumption in China, with the country becoming the largest energy supplier and consumer worldwide. Due to inter-fuel substitution of crude oil and inter-market contagion of international coal market, China's coal price might be interrelated with crude oil price and international coal price. However, the precise roles of these two effects in determining China's coal price are unknown. This paper contributes to previous literature by investigating this issue. We find that co-movements between China's coal price and crude oil price largely hinge on the shares of oil and coal in China’s energy mix, while its co-movements with international coal price depend on scales of coal trade. Inter-fuel substitution dominated the interaction of China's coal market with other energy types, but the importance of inter-market contagion has been increasing. We also find that China might have become an originator for driving the returns of crude oil and international coal, in particular after 2008. Furthermore, China's coal market is still a net volatility recipient for shocks from both crude oil market and international coal market. Given the increased integration of global energy markets, we anticipate this paper to provide a better understanding on the dynamic changes in China's coal prices
MVDream: Multi-view Diffusion for 3D Generation
We propose MVDream, a multi-view diffusion model that is able to generate
geometrically consistent multi-view images from a given text prompt. By
leveraging image diffusion models pre-trained on large-scale web datasets and a
multi-view dataset rendered from 3D assets, the resulting multi-view diffusion
model can achieve both the generalizability of 2D diffusion and the consistency
of 3D data. Such a model can thus be applied as a multi-view prior for 3D
generation via Score Distillation Sampling, where it greatly improves the
stability of existing 2D-lifting methods by solving the 3D consistency problem.
Finally, we show that the multi-view diffusion model can also be fine-tuned
under a few shot setting for personalized 3D generation, i.e. DreamBooth3D
application, where the consistency can be maintained after learning the subject
identity.Comment: Our project page is https://MV-Dream.github.i
GNFactor: Multi-Task Real Robot Learning with Generalizable Neural Feature Fields
It is a long-standing problem in robotics to develop agents capable of
executing diverse manipulation tasks from visual observations in unstructured
real-world environments. To achieve this goal, the robot needs to have a
comprehensive understanding of the 3D structure and semantics of the scene. In
this work, we present , a visual behavior cloning agent for
multi-task robotic manipulation with eneralizable eural
feature ields. GNFactor jointly optimizes a generalizable neural
field (GNF) as a reconstruction module and a Perceiver Transformer as a
decision-making module, leveraging a shared deep 3D voxel representation. To
incorporate semantics in 3D, the reconstruction module utilizes a
vision-language foundation model (, Stable Diffusion) to distill
rich semantic information into the deep 3D voxel. We evaluate GNFactor on 3
real robot tasks and perform detailed ablations on 10 RLBench tasks with a
limited number of demonstrations. We observe a substantial improvement of
GNFactor over current state-of-the-art methods in seen and unseen tasks,
demonstrating the strong generalization ability of GNFactor. Our project
website is https://yanjieze.com/GNFactor/ .Comment: CoRL 2023 Oral. Website: https://yanjieze.com/GNFactor
Large datasets of water vapor sorption, mass diffusion immersed in water, hygroscopic expansion and mechanical properties of flax fibre/shape memory epoxy hygromorph composites
This data article presents four experimental sets of results related to flax fibre composites with epoxy shape memory polymer matrix: water vapor absorption, mass diffusion immersed in water, hygroscopic expansion, mechanical properties. The water vapor absorption tests are described in raw data related to four types of laminates with weights measured at different relative humidity (0%, 9%, 33%, 44%,75%, 85% and 100%). The mass diffusion experiments are related to weights of immersed samples over time. The unidirectional composite hygroscopic expansion is also measured along the fibre longitude and transverse directions. The mechanical properties of flax composite at various temperatures (20°C, 40°C, 60°C, 80°C and 100°C) and humidity environments (50% and immersed) are also described. Load-displacement diagrams of the hygromorph composites are converted into stress-strain diagrams via a compliance calibration, from which the tensile moduli are extracted. The data presented in this article can provide a benchmark for the development of new models, or for the determination of other properties via post processing. The detailed interpretation of the data can be found in [1]. The data is available in the Mendeley Data repository at [2]
Analytical modelling, design and performance evaluation of chatter-free milling cutter with alternating pitch variations
Biobased and Programmable Electroadhesive Metasurfaces
[Image: see text] Electroadhesion has shown the potential to deliver versatile handling devices because of its simplicity of actuation and rapid response. Current electroadhesion systems have, however, significant difficulties in adapting to external objects with complex shapes. Here, a novel concept of metasurface is proposed by combining the use of natural fibers (flax) and shape memory epoxy polymers in a hygromorphic and thermally actuated composite (HyTemC). The biobased material composite can be used to manipulate adhesive surfaces with high precision and controlled environmental actuation. The HyTemC concept is preprogrammed to store controllable moisture and autonomous desorption when exposed to the operational environment, and can reach predesigned bending curvatures up to 31.9 m(–1) for concave and 29.6 m(–1) for convex shapes. The actuated adhesive surface shapes are generated via the architected metasurface structure, incorporating an electroadhesive component integrated with the programmable biobased materials. This biobased metasurface stimulated by the external environment provides a large taxonomy of shapes—from flat, circular, single/double concave, and wavy, to piecewise, polynomial, trigonometric, and airfoil configurations. The objects handled by the biobased metasurface can be fragile because of the high conformal matching between contacting surfaces and the absence of compressive adhesion. These natural fiber-based and environmentally friendly electroadhesive metasurfaces can significantly improve the design of programmable object handling technologies, and also provide a sustainable route to lower the carbon and emission footprint of smart structures and robotics
Anisotropic, Intermediate Coupling Superconductivity in Cu0.03TaS2
The anisotropic superconducting state properties in Cu0.03TaS2 have been
investigated by magnetization, magnetoresistance, and specific heat
measurements. It clearly shows that Cu0.03TaS2 undergoes a superconducting
transition at TC = 4.03 K. The obtained superconducting parameters demonstrate
that Cu0.03TaS2 is an anisotropic type-II superconductor. Combining specific
heat jump = 1.6(4), gap ratio 2/kBTC = 4.0(9) and the estimated electron-phonon
coupling constant ~ 0.68, the superconductivity in Cu0.03TaS2 is explained
within the intermediate coupling BCS scenario. First-principles electronic
structure calculations suggest that copper intercalation of 2H-TaS2 causes a
considerable increase of the Fermi surface volume and the carrier density,
which suppresses the CDW fluctuation and favors the raise of TC.Comment: 16pages, 5figure
Construction and validation of a glioblastoma prognostic model based on immune-related genes
BackgroundGlioblastoma multiforme (GBM) is a common malignant brain tumor with high mortality. It is urgently necessary to develop a new treatment because traditional approaches have plateaued.PurposeHere, we identified an immune-related gene (IRG)-based prognostic signature to comprehensively define the prognosis of GBM.MethodsGlioblastoma samples were selected from the Chinese Glioma Genome Atlas (CGGA). We retrieved IRGs from the ImmPort data resource. Univariate Cox regression and LASSO Cox regression analyses were used to develop our predictive model. In addition, we constructed a predictive nomogram integrating the independent predictive factors to determine the one-, two-, and 3-year overall survival (OS) probabilities of individuals with GBM. Additionally, the molecular and immune characteristics and benefits of ICI therapy were analyzed in subgroups defined based on our prognostic model. Finally, the proteins encoded by the selected genes were identified with liquid chromatography-tandem mass spectrometry and western blotting (WB).ResultsSix IRGs were used to construct the predictive model. The GBM patients were categorized into a high-risk group and a low-risk group. High-risk group patients had worse survival than low-risk group patients, and stronger positive associations with multiple tumor-related pathways, such as angiogenesis and hypoxia pathways, were found in the high-risk group. The high-risk group also had a low IDH1 mutation rate, high PTEN mutation rate, low 1p19q co-deletion rate and low MGMT promoter methylation rate. In addition, patients in the high-risk group showed increased immune cell infiltration, more aggressive immune activity, higher expression of immune checkpoint genes, and less benefit from immunotherapy than those in the low-risk group. Finally, the expression levels of TNC and SSTR2 were confirmed to be significantly associated with patient prognosis by protein mass spectrometry and WB.ConclusionHerein, a robust predictive model based on IRGs was developed to predict the OS of GBM patients and to aid future clinical research
Ancient and recent collisions revealed by phosphate minerals in the Chelyabinsk meteorite
AbstractThe collision history of asteroids is an important archive of inner Solar System evolution. Evidence for these collisions is brought to Earth by meteorites. However, as meteorites often preserve numerous impact-reset mineral ages, interpretation of their collision histories is controversial. Here, we combine analysis of phosphate U-Pb ages and microtextures to interpret the collision history of Chelyabinsk—a highly shocked meteorite. We show that phosphate U-Pb ages correlate with phosphate microtextural state. Pristine phosphate domain U-Pb compositions are generally concordant, whereas fracture-damaged domains universally display discordance. Combining both populations best constrains upper (4473 ± 11 Ma) and lower intercept (−9 ± 55 Ma, i.e., within error of present) U-Pb ages. All phosphate U-Pb ages were completely reset during an ancient high energy collision, whilst fracture-damaged domains experienced further Pb-loss during mild and recent collisional re-heating. Targeting textural sub-populations of phosphate grains permits more robust reconstruction of asteroidal collision histories.</jats:p
Recommended from our members
A solar wind-derived water reservoir on the Moon hosted by impact glass beads
The past two decades of lunar exploration have seen the detection of substantial quantities of water on the Moon’s surface. It has been proposed that a hydrated layer exists at depth in lunar soils, buffering a water cycle on the Moon globally. However, a reservoir has yet to be identified for this hydrated layer. Here we report the abundance, hydrogen isotope composition and core-to-rim variations of water measured in impact glass beads extracted from lunar soils returned by the Chang’e-5 mission. The impact glass beads preserve hydration signatures and display water abundance profiles consistent with the inward diffusion of solar wind-derived water. Diffusion modelling estimates diffusion timescales of less than 15 years at a temperature of 360 K. Such short diffusion timescales suggest an efficient water recharge mechanism that could sustain the lunar surface water cycle. We estimate that the amount of water hosted by impact glass beads in lunar soils may reach up to 2.7 × 1014 kg. Our direct measurements of this surface reservoir of lunar water show that impact glass beads can store substantial quantities of solar wind-derived water on the Moon and suggest that impact glass may be water reservoirs on other airless bodies
- …